The invention relates to a fluid box/manifold assembly for a heat exchanger, in particular of a motor vehicle.
It applies to the various types of heat exchangers which may be encountered in a vehicle, whether these are the radiator for heating the passenger compartment, or the radiator for cooling the engine, the condenser of the air-conditioning circuit, or even the evaporator of the air-conditioning circuit.
These heat exchangers consist of a bundle of parallel tubes, provided with fins, carrying out the thermal exchange with the external medium. The tubes of the bundle are linked, at least at one of their ends, by an end unit defining the flow direction of the fluid in the various tubes and allowing the fluid to be introduced into the exchanger and to be extracted therefrom. In the majority of cases, the bundle is linked to two end units.
Each of the end units includes a metal manifold plate, or "hole plate", into which the tubes of the bundle open out, these tubes being secured to this plate, for example by brazing, at the point where they open out. This plate, generally referred to as the "manifold", is capped by a cover or "fluid box" so that the manifold and the box define a common volume into which the corresponding ends of the tubes open out, and through which the fluid enters and leaves as appropriate.
The fluid box is provided with connections to ducts for intake and collection of fluid. Its internal volume may be furthermore subdivided into a plurality of separate subvolumes allowing certain groups of tubes in the bundle to be joined together so as to define a predetermined configuration for fluid flow in the exchanger, with optionally several round trips of fluid in the tube bundle. Hence, an end unit therefore comprises at least one manifold and one fluid box which need to be assembled jointly.
Until now, the manifold and the fluid box have been formed by separate elements which then need to be assembled, either by a brazing technique or by a mechanical assembling technique.